Bar codes and similar recording schemes are widely used today to mark objects in order to provide rapidly readable codes containing information relating to the the object such as its identity or price. Such codes usually consist of a series of printed bars of varying widths, similarly and/or differently spaced from each other and arranged to produce a particular reflectivity pattern when the bars are scanned sequentially with a light beam such as laser beam in a direction transverse to the orientation of the bars. The present invention relates to improvements in product or production coding and methods for scanning such coding. In certain applications, it is advantageous to provide in the same area or areas containing one or more of the bar codes, additional information which may be read or not as desired. The invention is directed toward an object marking arrangement employing conventional bar codes or similar markings in which auxiliary information is also encoded along one or more of the discrete marks or bars and/or in the spacings therebetween in a direction parallel to the bar. The auxiliary code may be an optical one so as to be readable by an electro-optical transducer (which may be the same or different from the transducer used to read the bar code) or magnetically recorded on a magnetic medium.
In a preferred form of the invention, a bar code is printed or otherwise formed on a product, workpiece, tool or label and additional information is provided longitudinally along one or more of the bars thereof by voids in the printing effected during or after printing. A pulsed laser beam may be used to pit or remove selected portions of the material making up the bars to define one or more electro-optically readable codes which may be sequentially or simultaineously electro-optically scanned with or without electro-optically scanning the bar code itself. In another form, one or more of the bars of a bar code may be printed with ink of a different color to provide auxilliary information or may contain magnetic recording ink defining digital and/or analog recordings. Reading may be effected by line scanning laterally across one or more bars, by raster scanning normal to the bars and/or by such scanning parallel to or along the longitudinal axis of the bars with or without scanning to detect the code defined by the bar codes. Codes other than so-called bar codes may thus be scanned per se or may have coded portions thereof also scanned to provide auxiliary information in addition to the primary information defined by the bars and their spacings or other indicia.
It is therefore a primary object of the present invention to provide an object marking and coding arrangement in which bar codes, or similar optically readable markings, have auxiliary information encoded within and/or between the discrete markings making up the bar code.
It is a further object for the auxiliary information to be made up of electro-optically scannable elements such as voids, pits, or marks of different color than the bars.
It is a further object for the auxiliary information to be made up of magnetic recordings readable by a magnetic pick-up.
Other objects, features, and advantages of the invention will become evident in light of the following detailed description considered in conjunction with the referenced drawings of a preferred exemplary embodiment according to the present invention.